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So                PRACTICAL ORGANIC CHEMISTRY

times its weight of a mixture of 2 vols. water and 3'vols. con-
centrated sulphuric acid for an hour with a long upright tube
or air-condenser. Distil a few c.c. of liquid, and test the distillate
for acetic acid, 2GH;,CN + H2S04 + 4H,O = 2CH:,COOH +
(NH4)2S04. See Appendix, p. 244-
PREPARATION 14.
Methylamine Hydrochloride, CH;>.NH:,.HC1.
Wurtz, Comptrend., 1848, 28, 223 ; Hofmann, 5fr., 1882, H,
2725, and JBer., 1883,15, 47 and 762.
20 grms. acetamide
54         (18 c.c.) bromine
56         caustic potash.
The dry acetamide and bromine are mixed in a flask ( litre),
and whilst the mixture is cooled in water, a 10 per cent,
solution of caustic potash (about 20 grams KOH) is added,
until the dark brown liquid changes to a deep yellow colour.
The solution, which now contains potassium bromide and
acetmonobromamide, is slowly added from a tap-funnel in-
serted, together with a thermometer, into the neck of a distilling
flask (i litre). The flask contains a concentrated solution of
caustic potash (56 grams in 100 c.c. of water), heated to 6070.
Heat is evolved, and care must be taken that the rise of tem-
perature does not greatly exceed the above limits. The reaction
goes on quietly, and the yellow solution is gradually decolourised.
The mixture is then digested for a short time at the above
temperature until the yellow colour completely disappears. A
few bits of broken pot are now introduced into the flask, which
is closed with an ordinary cork, and the liquid distilled over
wire-gauze. The vapours of. methylamine and ammonia, which
are cooled, are passed by means of a bent adapter, attached to
I fl         *                    the end of the condenser, into dilute hydrochloric acid contained
in the receiver. Care must be taken that the adapter does not
dip too far into the acid, or liquid may }>e sucked back into the
condenser and distilling flask. When the distillate is no longer
alkaline, and consequently all the methylamine has been driven
over, the hydrochloric acid solution is evaporated to dryness on
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